1. Technical Field
The present invention relates to a vibrating device and an electronic apparatus.
2. Related Art
Heretofore, vibrating devices in which a sensor chip and an IC (Integrated Circuit) are disposed within a casing have been known (for example, refer to JP-A-2006-261560 (Patent Document 1)).
A vibrating device (semiconductor package) of Patent Document 1 has a case body having a bottom plate and a frame-like side wall disposed at a peripheral edge portion of an upper surface of the bottom plate. A sensor chip such as an acceleration sensor, a signal processing chip, and a memory chip are mounted on the upper surface of the bottom plate so as to be located in a chip accommodating space formed in the interior of the case body.
Moreover, in the vibrating device of Patent Document 1, the signal processing chip and the memory chip are arranged to be overlapped with each other in the thickness direction, and the sensor chip is arranged in parallel next to them. The bottom plate is designed such that the thickness of a sensor chip mounting area in which the sensor chip is mounted is smaller than that of a signal processing chip mounting area in which the signal processing chip and the memory chip are arranged to be overlapped with each other. In other words, the bottom plate has a shape in which one portion (portion corresponding to the sensor chip mounting area) of the upper surface is recessed lower than the other portion (portion corresponding to the signal processing chip mounting area). In the recessed portion, the sensor chip is mounted. In the vibrating device of Patent Document 1, by mounting the sensor chip having a thickness greater than that of the signal processing chip or the memory chip in the recessed portion, miniaturization (reduction in profile) of the vibrating device is achieved.
In the vibrating device of Patent Document 1, however, the thickness of the sensor chip mounting area of the bottom plate is reduced, and the sensor chip is mounted in the thickness-reduced portion. The thickness-reduced portion is easy to deform (easy to strain) due to an external force or heat, compared to the other portion (signal processing chip mounting area). Then, due to deformation occurring in the portion, an unexpected external force (stress) is applied to the sensor chip, thereby reducing detection accuracy of the sensor chip.
In this manner, the vibrating device of Patent Document 1 has a problem that it is impossible to achieve miniaturization while preventing a reduction in characteristics.